money-module/src/main/kotlin/com/cubetiqs/money/MoneyConfig.kt

package com.cubetiqs.money

import java.util.*
import java.util.concurrent.ConcurrentHashMap
import java.util.concurrent.ConcurrentMap

/**
 * Default money config in static object.
 * Sample parse format: USD=1,KHR=4000,EUR=0.99
 *
 * @author sombochea
 * @since 1.0
 */
object MoneyConfig {
    private const val CONFIG_INITIAL_SIZE = 10
    private const val CONFIG_FORMATTER_INITIAL_SIZE = 10
    private const val LOCALES_INITIAL_SIZE = 5
    private const val CURRENCIES_INITIAL_SIZE = 5

    /**
     * All money currencies and its rate are stored in memory state for exchange or compute the value.
     *
     * Key is the currency
     * Value is the rate
     */
    private val configRates: ConcurrentMap<String, Double> = ConcurrentHashMap(CONFIG_INITIAL_SIZE)

    // use to format the money for each value, if have
    private val configFormatter: ConcurrentMap<String, MoneyFormatProvider> =
        ConcurrentHashMap(CONFIG_FORMATTER_INITIAL_SIZE)

    // use to custom locales and allow to detect auto formatter, if enable auto locale format
    private val configLocales: ConcurrentMap<String, Locale> = ConcurrentHashMap(LOCALES_INITIAL_SIZE)

    // use to custom currencies and allow to detect auto, when use auto detect for currencies translate
    private val configCurrencies: ConcurrentMap<String, Currency> = ConcurrentHashMap(CURRENCIES_INITIAL_SIZE)

    // use to auto format, when this true
    // and formatter for money value, with current locale or custom set locale
    private var autoLocaleFormatter: Boolean = false

    // use to auto format, when this true
    // and formatter for money value, with current currency or custom set currency
    private var autoCurrencyFormatter: Boolean = false

    // use to identified for config dataset with prefix mode
    private var configPrefix: String = ""
    private fun isConfigPrefixValid() = configPrefix.isNotEmpty() && configPrefix.isNotBlank()

    // use to fallback, if the currency not found
    // if the fallback greater than ZERO, then called it
    // else throws
    private var fallbackRate: Double = 0.0

    fun getConfigs(): Map<String, Any?> {
        return mapOf(
            "configRates" to configRates,
            "configFormatter" to configFormatter,
            "configLocales" to configLocales,
            "configCurrencies" to configCurrencies,
        )
    }

    // validate the config rates, if have it's valid
    fun isConfigRatesValid(): Boolean {
        return configRates.isNotEmpty()
    }

    /**
     * Money properties for money config format
     */
    private var properties: MoneyConfigProperties? = null

    private val propertiesBuilder = MoneyConfigProperties.MoneyConfigPropertiesBuilder()

    private fun getProperties(): MoneyConfigProperties {
        return properties ?: propertiesBuilder.build()
    }

    fun setProperties(properties: MoneyConfigProperties): MoneyConfig {
        MoneyConfig.properties = properties
        return MoneyConfig
    }

    fun setConfigPrefix(prefix: String): MoneyConfig {
        configPrefix = prefix
        return MoneyConfig
    }

    fun setFallbackRate(fallbackRate: Double) = apply {
        this.fallbackRate = fallbackRate
    }

    fun setAutoLocaleFormatter(enabled: Boolean) = apply {
        this.autoLocaleFormatter = enabled
    }

    fun setAutoCurrencyFormatter(enabled: Boolean) = apply {
        this.autoCurrencyFormatter = enabled
    }

    fun isAutoLocaleFormatterEnabled() = this.autoLocaleFormatter
    fun isAutoCurrencyFormatterEnabled() = this.autoCurrencyFormatter

    // get custom config key within currency generally
    // example: myOwned_usd
    private fun getConfigKey(key: String): String {
        if (configPrefix.isEmpty() || configPrefix.isBlank()) {
            return key
        }
        return "${configPrefix}_$key"
    }

    /**
     * Parse the config string to currency's map within rates
     * Key is money's currency (String)
     * Value is money's value (Double)
     *
     * Example for config rules: usd:1,khr:4000
     */
    fun parse(config: String, clearAllStates: Boolean = true) {
        // remove all states, if needed
        if (clearAllStates) {
            if (!isConfigPrefixValid()) {
                configRates.clear()
            } else {
                val keys = configRates.filter { it.key.startsWith(prefix = configPrefix) }.keys
                keys.forEach { key ->
                    configRates.remove(key)
                }
            }
        }

        val rates = config.split(getProperties().deliSplit)
        rates.map { i ->
            val temp = i
                // remove the quote from string
                .replace("\"", "")
                .split(getProperties().deliEqual)
            if (temp.size == 2) {
                val currency = temp[0]
                    .toUpperCase()
                    .trim()
                val key = getConfigKey(currency)
                val value = temp[1].toDouble()

                // set the value into dataset
                if (configRates.containsKey(key)) {
                    configRates.replace(key, value)
                } else {
                    configRates.put(key, value)
                }
            } else {
                throw MoneyCurrencyStateException("money config format $temp is not valid!")
            }
        }
    }

    // append the rate into dataset
    // for config key are completed change inside
    fun appendRate(currency: String, rate: Double) = apply {
        val currencyKey = currency.toUpperCase().trim()
        val key = getConfigKey(currencyKey)
        if (configRates.containsKey(key)) {
            configRates.replace(key, rate)
        } else {
            configRates[key] = rate
        }
    }

    // append the rate via provider
    // no need to change currency prefix
    fun appendRate(provider: MoneyExchangeProvider) = apply {
        val currency = provider.getCurrency()
        val rate = provider.getRate()
        this.appendRate(currency, rate)
    }

    /**
     * Json Format must be, example below
     *
     * {
     *  "USD": 1,
     *  "EUR": 0.99,
     *  "...": ...
     * }
     */
    fun fromJsonRates(configJson: String, clearAllStates: Boolean = false) {
        val transformValues = configJson
            .removePrefix("{")
            .removeSuffix("}")

        parse(transformValues, clearAllStates)
    }

    // all currencies with its rate
    fun getConfigRates() = configRates

    @Throws(MoneyCurrencyStateException::class)
    fun getRate(currency: StdMoney.Currency): Double {
        return getConfigRates()[getConfigKey(currency.getCurrency().toUpperCase().trim())]
            ?: if (fallbackRate > 0) fallbackRate else throw MoneyCurrencyStateException("money currency ${currency.getCurrency()} is not valid!")
    }

    // apply custom locale below
    fun applyDefaultLocale(locale: Locale = Locale.getDefault()) = apply {
        configLocales[MoneyFormatter.DEFAULT_LOCALE] = locale
    }

    // get default locale from system or user defined
    private fun getDefaultLocale(): Locale {
        return configLocales[MoneyFormatter.DEFAULT_LOCALE] ?: Locale.getDefault()
    }

    // add custom locale
    fun applyLocale(locale: Locale) = apply {
        if (isConfigPrefixValid()) {
            if (configLocales.containsKey(configPrefix)) {
                configLocales.replace(configPrefix, locale)
            } else {
                configLocales[configPrefix] = locale
            }
        }
    }

    // get locale by config prefix or default if not found
    fun getLocale(): Locale {
        if (isConfigPrefixValid() && configLocales.containsKey(configPrefix)) {
            return configLocales[configPrefix] ?: getDefaultLocale()
        }

        return getDefaultLocale()
    }

    // get default currency from system or user defined
    private fun getDefaultCurrency(): Currency {
        return configCurrencies[MoneyFormatter.DEFAULT_CURRENCY] ?: Currency.getInstance(getDefaultLocale())
    }

    // apply the default currency for system at runtime
    fun applyDefaultCurrency(currency: StdMoney.Currency) = apply {
        configCurrencies[MoneyFormatter.DEFAULT_CURRENCY] = currency.findCurrency()
    }

    // apply the currency into the config for system currency at runtime
    fun applyCurrency(currency: StdMoney.Currency) = apply {
        if (isConfigPrefixValid()) {
            val systemCurrency = currency.findCurrency()
            if (systemCurrency != null) {
                if (configCurrencies.containsKey(configPrefix)) {
                    configCurrencies.replace(configPrefix, systemCurrency)
                } else {
                    configCurrencies[configPrefix] = systemCurrency
                }
            }
        }
    }

    // get currency by config prefix or default if not found
    fun getCurrency(): Currency {
        if (isConfigPrefixValid() && configCurrencies.containsKey(configPrefix)) {
            return configCurrencies[configPrefix] ?: getDefaultCurrency()
        }

        return getDefaultCurrency()
    }

    fun getCurrencySymbol(): String {
        return getCurrency().getSymbol(getDefaultLocale())
    }

    // apply default formatter for all not exists
    fun applyDefaultFormatter(
        provider: MoneyFormatProvider? = null
    ) = apply {
        configFormatter[MoneyFormatter.DEFAULT_FORMATTER] = buildMoneyFormatter {
            setProvider(provider)
        }
    }

    // add money formatter by currency of each money value
    fun addFormatter(currency: String, formatter: MoneyFormatProvider) = apply {
        val key = getConfigKey(currency.toUpperCase().trim())
        if (configFormatter.containsKey(key)) {
            configFormatter.replace(key, formatter)
        } else {
            configFormatter[key] = formatter
        }
    }

    // get formatter by currency or default
    fun getFormatter(currency: String? = null): MoneyFormatter {
        // apply default formatter
        val formatter = (if (!currency.isNullOrEmpty()) {
            val key = getConfigKey(currency.toUpperCase().trim())
            configFormatter[key]
        } else {
            null
        }) ?: configFormatter[MoneyFormatter.DEFAULT_FORMATTER]

        return when (formatter) {
            is MoneyFormatter -> formatter
            else -> buildMoneyFormatter { setProvider(provider = formatter) }
        }
    }

    class MoneyConfigProperties(
        val deliEqual: Char,
        val deliSplit: Char,
    ) {
        class MoneyConfigPropertiesBuilder(
            private var deliEqual: Char? = null,
            private var deliSplit: Char? = null,
        ) {
            fun setDeliEqual(deliEqual: Char) = apply { this.deliEqual = deliEqual }

            private fun getDeliEqual(): Char {
                return deliEqual ?: '='
            }

            fun setDeliSplit(deliSplit: Char) = apply { this.deliSplit = deliSplit }

            private fun getDeliSplit(): Char {
                return deliSplit ?: ','
            }

            fun build(): MoneyConfigProperties {
                return MoneyConfigProperties(deliEqual = getDeliEqual(), deliSplit = getDeliSplit())
            }
        }
    }

    fun builder() = MoneyConfigProperties.MoneyConfigPropertiesBuilder()
}